The Intro slide is a slider created when your app was first created. If you are replacing it, it must be have the title "Intro" to be displayed when the app is opened the first time.

Wrapper tag
<ion-slides pager>
  <-- ion-slide tags -->

Slide markup
For each slide item you want, copy this ion-slide markup and replace {{ion-icon}}, {{your title}} and {{your content goes here}}. You can find all the ion-icons here.

  <div class="icon-hero"><ion-icon name="{{ion-icon}}"></ion-icon></div>
  <h2 class="slide-title">{{your title}}</h2>
  <p>{{your content goes here}}</p>
  <!-- optional button goes here -->

Optional button
If you would like to have a button that links to a menu item, the <button></button> markup will look like this:

<button ion-button large (click)="openPage(pages.menus.items[0])">
  {{button text}}
  <ion-icon name="{{ion-icon}}"></ion-icon>

Link to pages
pages.menus.items[0] will open the first item and pages.menus.items[1] will open the second.

Full Sample Markup
See the template in your app builder.